Mucinous Tubular and Spindle Cell Carcinoma: A Case Report and Review of the Literature

Abstract

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare epithelial renal tumor, first recognized as a distinct subtype of renal cell carcinoma (RCC) in the 2004 WHO classification. It is characterized by low malignant potential and typically indolent clinical behavior. Due to its rarity and overlapping imaging features with other renal tumors, accurate preoperative diagnosis remains challenging. We report the case of a 42-year-old woman presenting with painless, non-clotting gross hematuria persisting for four months. Ultrasound revealed a suspicious renal mass, which was further evaluated by contrast-enhanced CT, showing a 12 cm heterogeneous lesion in the lower pole of the right kidney. The mass demonstrated areas of hemorrhage and punctate calcifications, along with delayed, progressive enhancement. There was no evidence of adjacent organ invasion. Histopathological examination following right radical nephrectomy confirmed the diagnosis of MTSCC. Although the definitive diagnosis relies on histological examination, imaging plays a key role in detecting the tumor, assessing its contrast enhancement pattern, evaluating its morphological characteristics, and determining the extent of the lesion. These elements help guide the preoperative diagnosis, suggest potential histological subtypes, and support appropriate management planning, particularly in terms of surgical approach.